An aspirin a day may help keep tumors away, according to a study done in part at the University of Iowa. Doctor Robert Summers, a U-of-I professor of internal medicine, says a daily dose of aspirin can be effective in reducing the risk of colon adenomas — benign tumors or polyps — in people who previously have had the polyps. Dr. Summers says the benign tumors can develop into cancer if left in the bowel. He says it’s fairly miraculous that an inexpensive, widely available, non-prescription drug like aspirin can have such a positive impact on this cancer killer.Summers says colon cancer is a killer in Iowa and nationwide, but when detected early, it can often be treated successfully. He says about a thousand Iowans will develop colon cancer in the next year and between 300 and 400 will die from it. University of Iowa researchers contributed to the study, headed by the Dartmouth Medical School, which appears in the March 6 issue of the New England Journal of Medicine.